Human liver sinusoidal endothelial cells support the development of functional human pluripotent stem cell-derived Kupffer cells.

In mice, the first liver-resident macrophages, known as Kupffer cells (KCs), are thought to derive from yolk sac (YS) hematopoietic progenitors that are specified prior to the emergence of the hematopoietic stem cell (HSC). To investigate human KC development, we recapitulated YS-like hematopoiesis from human pluripotent stem cells (hPSCs) and transplanted derivative macrophage progenitors into NSG mice previously humanized with hPSC-liver sinusoidal endothelial cells (LSECs). We demonstrate that hPSC-LSECs facilitate stable hPSC-YS-macrophage engraftment for at least 7 weeks. Single-cell RNA sequencing (scRNA-seq) of engrafted YS-macrophages revealed a homogeneous MARCO- expressing KC gene signature and low expression of monocyte-like macrophage genes. In contrast, human cord blood (CB)-derived macrophage progenitors generated grafts that contain multiple hematopoietic lineages in addition to KCs. Functional analyses showed that the engrafted KCs actively perform phagocytosis and erythrophagocytosis in vivo. Taken together, these findings demonstrate that it is possible to generate human KCs from hPSC-derived, YS-like progenitors. [Display omitted] • hPSC yolk-sac-like progenitors form homogeneous human KC grafts in NSG-LSEC mice • hPSC-KCs with a tissue-resident MARCO gene signature persist (7+ weeks) in the liver • hPSC-KCs perform phagocytotic and erythrophagocytotic homeostatic functions in vivo • Cultured CB progenitors form human KCs with heterogeneous grafts in NSG-LSEC mice Kent et al. demonstrate that hPSC-derived, yolk-sac-like macrophage progenitors mature into functional Kupffer cells (KCs) when transplanted into NSG mice humanized with hPSC-derived liver sinusoidal endothelial cells. These hPSC-KCs are transcriptionally similar to human fetal and adult KCs, expressing the tissue-resident genes MARCO , CD5L , and TIMD4. [ABSTRACT FROM AUTHOR]